21248032 has 36 divisors (see below), whose sum is σ = 45308970. Its totient is φ = 9804288.

The previous prime is 21248009. The next prime is 21248047. The reversal of 21248032 is 23084212.

It can be written as a sum of positive squares in 3 ways, for example, as 6533136 + 14714896 = 2556^2 + 3836^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21247994 and 21248012.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3444 + ... + 7372.

Almost surely, 2^21248032 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21248032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22654485).

21248032 is an abundant number, since it is smaller than the sum of its proper divisors (24060938).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21248032 is a wasteful number, since it uses less digits than its factorization.

21248032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3965 (or 3944 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 21248032 is about 4609.5587641335. The cubic root of 21248032 is about 276.9743619483.

The spelling of 21248032 in words is "twenty-one million, two hundred forty-eight thousand, thirty-two".